The major objective of the project during the period from l977 to l980 is to complete a six year longitudinal follow-up of decision making, memory, and learning processes that involves about 250 participants in the Normative Aging Study. The instrumentation and procedures for conducting the follow-up longitudinal study were completed and the first subject was retested in December of l977, almost exactly six years after his initial testing. Between December 22, l977 and March 27, l978, 40 subjects have been retested, 20 other contacted, and only l7 subjects have refused to be retested or are unavailable for testing. Persons who indicated that they do not want to come back for retesting are being encouraged to come back for the follow-up. The design of the longitudinal study calls for a comparison group of subjects of the Normative Aging Study, that was seen on the original testing. The data from this group will provide a check on the validity of the longitudinal findings that might emerge from the study. The testing of these additional subjects will begin May l978. In the supplement to the parent grant, several new cross sectional studies were proposed. None of these were performed because of the uncertainty of funding of the supplemental grant during the grant year that is ending. The new studies will be conducted in the remaining years of the Mental Performance and Aging project.